No abstract

The expansion of the Brookhaven accelerator facilities, and the ongoing efforts to raise the AGS beam intensity, have been a driving force for the addition of new kickers and the upgrading of older ones to meet this challenge. All kicker power supply systems are running above their design specifications to provide wider operating ranges. The newly upgraded Booster fast extraction kicker power supply was commissioned in September 1997. Its compact high voltage modulator structure offers a pulse length almost three times longer than the preceding package within the confines of the same physical space. The AGS A5 injection kicker and the AGS G10 extraction kickers are also discussed. In order to expedite design, assembly, and commissioning, and to facilitate interchangeability, standardized modules have been adopted where possible. This paper gives an overview of the AGS and Booster fast injection and extraction kicker systems including their parameters, structure and status.

Two ac dipoles with vertical and horizontal magnetic field have been proposed at RHIC for applications in linear and non-linear beam dynamics and spin manipulations. A magnetic field amplitude of 380 Gm is required to produce a coherent oscillation of 5 times the rms beam size at the top energy. We take the ac dipole frequency to be 1.0% of the revolution frequency away from the betatron frequency. To achieve the strong magnetic field with minimum power loss, an air-core magnet with two seven turn winding of low loss Litz wire resonating at 64 kHz is designed. The system is also designed to allow one to connect the two magnet winding in series to resonate at 37 kHz for the spin manipulation. Measurements of a half length prototype magnet are also presented.

The energy stored in the RHIC beam is about 200 kJ per ring at design energy and intensity. To prevent quenching of the superconducting magnets or material damage, the beam will be safely disposed of by an internal beam abort system, which includes the kicker magnets, the pulsed power supplies, and the dump absorber. Disposal of heavy ions, such as gold imposes design constraints more severe than those for proton beams of equal intensity. In order to minimize the thermal shock in the carbon-fiber dump block, the bunches must be laterally dispersed.The nominal horizontal beam deflection angle is required to vary from -1.7 to 2.5 mrad, which is obtained from five 1.22 m long kicker modules operating at a magnetic field of -3.5 T. The kickers are constructed as window frame magnets with an 50.8 by 76.2 mm aperture and are operated in the ring vacuum.The puked power supplies run at 33 kV and deliver the 12.8 us long pulse. The peak current required is -21 kA and the 50% modulation is generated by means of a pulse forming network with non-uniform characteristic impedance.

Its accelerating cavities are sveep-tuned by varying the permeabilitv of ferrite core rings vithin the cavities. Core material selection criteria and evaluation are discussed Measure-Tents of permeability, loss and perrni tt i" : ty .v.c presented.